In a modern semiconductor manufacturing facility, there is typically an Automated Material Handling System (AMHS) that transports semiconductor wafers to their proper fabrication stations. The AMHS system is comprised of a plurality of transport mechanisms to transport wafers inside of wafer carriers, monitors and sensors to track the positions of wafer carriers, and a computer system which manages this information and performs route optimizations to route the materials to the needed process tools in a way to promote high efficiency of the manufacturing facility. When a process tool finishes processing its current batch of wafers, the system keeps the production line moving by automatically determining the best lot to run next on the equipment.
Every carrier, as well as the wafers inside, is tracked continuously as it moves down the production line, and employees can track the status of a wafer at any stage in the production process. This helps prevent processing mistakes, and allows better inventory control as well as customer service.
The current AMHS is efficient at routing wafers to the needed processing tools in an efficient manner. However, there are limitations in the systems that exist today. The systems do not account for certain safety, business, and security requirements when it comes to the temporary storage of the batches of wafers (referred to as “lots”) and wafer carriers while awaiting the next phase in the manufacturing process. What is needed is an improved system for managing the entry of wafers into the temporary storage area.